From July 9 through July 12, two colleagues from the Mechanical Engineering PhD program at UC Berkeley and I joined a group of young professionals in ocean engineering at the 2019 North America International Network on Offshore Renewable Energy (INORE) conference. The event was held at Pearson College, less than an hour from Victoria, British Columbia, and had the purpose of connecting people and their ideas on the development of tidal, wave, and offshore wind energy.
One of the main applications of Marine Renewable Energy (MRE) is to power remote coastal communities. Based on the 2018 Clean Technology Integration in Remote Communities report, in Canada alone there are more than 260 remote communities established, with many near the coast and most relying on diesel generators for power supply. MREs could not only reduce the emission of greenhouse gases caused by the 335 million liters of diesel burned annually, but also give these communities a better quality of life. According to conference speaker Yuho Okada, president of the Barkley Project Group, the energy grid in remote communities is so unreliable that blackouts can last up to a week. Consequently, individuals often leave their homeland to work in urban locations where power outages are not common. This issue extends beyond just the Canadian community, potentially affecting every coastal community in the world that might not have access to a strong energy grid.
Despite its great potential to help meet the coastal demand for energy, MRE hasn’t become as popular as land-based wind and solar energies in the push for green electricity. The reason is quite simple: designing for the ocean is remarkably challenging. Not only do offshore devices have to be able to withstand salt water corrosion and algae growth, but they must also survive extreme weather conditions, such as high winds and strong waves during sea storms. After attending the conference, it’s clear to me, as a researcher in the field, that the main milestone that wave and tidal energy has yet to achieve is the demonstration of scalability and convergence of design: there are many different offshore energy converters out there that work at small scale, but increasing their power output to match higher energy demands remains a challenge. This is where fundamental research can help: understanding the basic physics of the ocean environment is critical to scale models without simply “making them bigger”. At the same time, there is no current agreement on which type of wave energy converter or tidal turbine design is best, with new mechanisms still popping up from many university labs. Once a reliable, durable, scalable, and efficient offshore energy converter is established and demonstrated, then the industry will be able to make heavy investments that will draw the cost of electricity from MRE devices down, making them more present in our coastal energy grid.
Knowing the challenges and the rewards ahead, the push for offshore energy continues. At UC Berkeley, for example, faculty and students are working both in the fundamental physics behind ocean technology and in more applied MRE engineering design. Eric Thacher, a graduate student from FLOW lab who presented his work at INORE, studies vortex-induced vibration from cross-flow over a cylinder in multiphase (air-water) flows . This is an important phenomenon that must be taken into consideration in tidal turbine design to avoid fatigue loading and undesired mechanical resonances in the turbine blades. Another Berkeley student who attended INORE was Michael Kelly, from the Theoretical and Applied Fluid Dynamics laboratory, who works on shape optimization and geometry control for wave energy converters (WECs). These models are of great importance to the survivability of WECs, as they help maximize the absorbed power while minimizing forces from storm waves by changing the shape of the device depending on wave conditions. I also work in FLOW lab studying air entrainment, or formation of air bubbles, due to plunging jets, which are liquid jets falling into a still liquid body, such as a waterfall into a lake or a wave into the ocean surface. This phenomenon is ever-present in breaking waves and contributes significantly to their energy dissipation during breaking, but hasn’t been thoroughly quantified and is not well-understood as of today. These topics studied at UC Berkeley address only a fraction of the complex problem of modelling and deploying MREs, but are nonetheless crucial to the overall success of the technology.
Attending the INORE conference was a great way for a young professional in ocean engineering like myself to understand more about the MRE field and make connections with the great research scientists and industry leaders working in this sector. Throughout the conference, I was able to to learn more about the opportunities for MREs to help power remote communities and about the main barriers for the technology, such as scalability of offshore structures and convergence of energy converter design. The challenges ahead notwithstanding, I’m excited to be conducting research that will help offshore sources of energy play their upcoming role in the clean and sustainable power grids of the future, and I’m looking forward to seeing MRE devices become pervasive throughout the world’s shores.
Note: Barkley Project Group is a business that provides technical support in developing infrastructure and sustainable energy for First Nation communities in British Columbia.
Featured Image: Big Sur.
Source: Jose Moreno.